The growth between the N64 version and the GC version occured simply because the GC version was superior on all fronts:
- Much more characters and stages
- Faster gameplay
- Adventure, Event, All-Star and Tournament mode (among many others) were introduced
- Trophies were introduced
- Ganondorf was playable
Super Smash Bros. Brawl messed things up a little with the awful Smash Ball and somewhat slower gameplay. But they made up for some of it with the level editor, replay saves and Subspace Emissary. In the end I'd say that the sales would have ended up slightly below Melee levels if it wasn't for the Wii's relatively massive hardware numbers.
As long as the series keep evolving while maintaining its core (which was shaken by the aforementioned Smash Ball), its popularity should keep growing.







